Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely useful behavior: the sanctioned true/false meaning, the matching lists returned, and the critical edge case that Cosmos bech32 addresses return sanctioned: null (unchecked, not clean) when unlisted. With no output schema, this disclosure is valuable, though error/rate-limit behavior is absent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the action and coverage, then edge cases, then a scope caveat. Four sentences are dense but each carries weight; only minor redundancy exists between the description and the schema's address guidance.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 1-param, read-only tool with no output schema, the description supplies the return semantics (true/false/null, matching lists) and chain coverage needed to interpret results correctly. It is nearly complete, missing only failure-mode handling.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% for the single address parameter, and the description largely restates the same format guidance (EVM/Bitcoin/bech32). Baseline 3 applies since the schema already documents the parameter; the description adds little beyond it here.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (screens) and resource (crypto address) plus the exact scope: every OFAC SDN digital currency address list. It names the covered address formats, so an agent can distinguish it from siblings like ip_reputation, url_reputation, or security_scan without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The closing sentence 'A sanctions signal only, not a full risk score' clearly bounds usage and warns against over-trusting the result. It lacks explicit routing to named alternatives (e.g. url_reputation for URLs), but the scope boundary is well stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.